Low pH-induced changes of antioxidant enzyme and ATPase activities in the roots of rice (Oryza sativa L.) seedlings

• Published in: PloS one Vol. 10; no. 2; p. e0116971
• Main Authors: Zhang, Yi-Kai, Zhu, De-Feng, Zhang, Yu-Ping, Chen, Hui-Zhe, Xiang, Jing, Lin, Xian-Qing
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 26.02.2015; Public Library of Science (PLoS)
• Subjects: Acidic soils; Acidification; Adenosine triphosphatase; Agricultural production; Aluminum; Antioxidants; Antioxidants (Nutrients); Ascorbate Peroxidases - genetics; Ascorbate Peroxidases - metabolism; Ascorbic acid; ATPases; Biology; Ca2+-transporting ATPase; Calcium; Calcium channels (P-type); Calcium ions; Calcium-Transporting ATPases - genetics; Calcium-Transporting ATPases - metabolism; Catalase; Catalase - genetics; Catalase - metabolism; Chimera - metabolism; Copper; Cultivars; Dry matter; Environmental impact; Enzymes; Gene expression; Genes; H+-transporting ATPase; Hydrogen; Hydrogen peroxide; Hydrogen-Ion Concentration; L-Ascorbate peroxidase; Laboratories; Lipid peroxidation; Lipids; Metabolism; Oryza - enzymology; Oryza - genetics; Oryza sativa indica; Oryza sativa japonica; Oxygen; Peroxidase; Peroxidation; pH effects; Physiological aspects; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Roots - enzymology; Plasma; Proton-Translocating ATPases - genetics; Proton-Translocating ATPases - metabolism; Reactive oxygen species; Rhizosphere; Rice; RNA, Messenger - genetics; RNA, Messenger - metabolism; Roots; Seedlings; Seedlings - enzymology; Seeds; Soil - chemistry; Soil acidification; Superoxide dismutase; Superoxide Dismutase - genetics; Superoxide Dismutase - metabolism; Superoxides; Transcription; Triticum; Zinc; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0116971

Soil acidification is the main problem in the current rice production. Here, the effects of low pH on the root growth, reactive oxygen species metabolism, plasma membrane functions, and the transcript levels of the related genes were investigated in rice seedlings (Oryza sativa L.) in a hydroponic system at pH 3.5, 4.5, and 5.5. There were two hybrid rice cultivars in this trial, including Yongyou 12 (YY12, a japonica hybrid) and Zhongzheyou 1 (ZZY1, an indica hybrid). Higher H+ activity markedly decreased root length, the proportion of fine roots, and dry matter production, but induced a significant accumulation of hydrogen peroxide (H2O2), and led to serious lipid peroxidation in the roots of the two varieties. The transcript levels of copper/zinc superoxide dismutase 1 (Cu/Zn SOD1), copper/zinc superoxide dismutase 2 (Cu/Zn SOD2), catalase A (CATA) and catalase B (CATB) genes in YY12 and ZZY1 roots were significantly down-regulated after low pH exposure for two weeks. Meanwhile, a significant decrease was observed in the expression of the P-type Ca2+-ATPases in roots at pH 3.5. The activities of antioxidant enzymes (SOD, CAT) and plasma membrane (PM) Ca2+-ATPase in the two varieties were dramatically inhibited by strong rhizosphere acidification. However, the expression levels of ascorbate peroxidase 1 (APX1) and PM H+-ATPase isoform 7 were up-regulated under H+ stress compared with the control. Significantly higher activities of APX and PM H+-ATPase could contribute to the adaptation of rice roots to low pH.